Task is similar to a job in Hadoop. Task is an execution entity. A topology must be defined inside a task. SAMOA can only execute classes that implement Task interface.

1. Implementation

package org.apache.samoa.tasks;

import org.apache.samoa.topology.ComponentFactory;
import org.apache.samoa.topology.Topology;

 * Task interface, the mother of all SAMOA tasks!
public interface Task {

     * Initialize this SAMOA task, 
     * i.e. create and connect Processors and Streams
     * and initialize the topology
    public void init(); 

     * Return the final topology object to be executed in the cluster
     * @return topology object to be submitted to be executed in the cluster
    public Topology getTopology();

     * Sets the factory.
     * TODO: propose to hide factory from task, 
     * i.e. Task will only see TopologyBuilder, 
     * and factory creation will be handled by TopologyBuilder
     * @param factory the new factory
    public void setFactory(ComponentFactory factory) ;

2. Methods

2.1 void init()

This method should build the desired topology by creating Processors and Streams and connecting them to each other.

2.2 Topology getTopology()

This method should return the topology built by init to the engine for execution.

2.3 void setFactory(ComponentFactory factory)

Utility method to accept a ComponentFactory to use in building the topology.